Mapping the upper mantle structure beneath the South Atlantic and the adjacent continents using full waveform tomography with geodynamic interpretations of hotspot flux and material transport in the asthenosphere.

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We propose to combine full waveform tomography and geodynamic forward modelling to address key questions concerning the geodynamics and evolution of the South Atlantic region: (1) How and to which extent does the South Atlantic plume system feed the asthenosphere in the oceanic basin and adjacent regions? (2) What are the current thermal states of the Walvis Ridge and the Etendeka and Paraná continental flood basalt? (3) What, if any, is the pathway of slow seismic material from the upper to the lower mantle? (4) Is the prominent topographic gradient across the South Atlantic region from Africa to South America explicable solely in terms of lower mantle structure, or do we also find a systematic gradient in upper mantle heterogeneity across the ocean basin? (5) What is the relation of upper mantle heterogeneity and anisotropic structure to the Mid-Atlantic ridge system and hotspots? The use of full waveform tomography will allow us to exploit as much information as possible from seismograms. Our approach is thus well suited for regions with comparatively low data coverage such as the South Atlantic. Mineral physics models will allow us to infer dynamically important constraints on lateral temperature variations in a thermodynamically self-consistent way from the seismic observations. Observations of seismic anisotropy and geodynamic modelling will help us to further quantify and substantiate our inferences on the thermal state and material flux in the South Atlantic upper mantle.